In the aforesaid co-pending application, Ser. No. 406,086, there is disclosed an annular composite washer assembly which provides a "soft" mount for the abrasive disc subassembly mounted on the threaded output spindle of a portable grinder. The composite washer assembly, which is disposed coaxially between the abrasive disc subassembly and an annular shoulder on the spindle, includes a pair of flat annular washers and a molded plastic body therebetween. The body has integrally-molded inner and outer annular bands joined integrally with the inner and outer diameters of the respective washers. The inner annular band is threadably received over the output spindle, and the threads on the spindle "bite" into the relatively soft plastic material of the band. As a result, an economical integral component is provided for mounting the abrasive disc subassembly on the output spindle and preventing the subassembly from inadvertently locking or jamming against the shoulder on the spindle. This insures that the abrasive disc subassembly may be easily removed from the spindle.